The effect of anti‐Xa monitoring on the safety and efficacy of low‐molecular‐weight heparin anticoagulation therapy: A systematic review and meta‐analysis

WHAT IS KNOWN AND OBJECTIVE: Low-molecular-weight heparin (LMWH) is widely used in the prevention and treatment of venous thromboembolism (VTE), and anti-Xa assay is the gold standard for monitoring LMWH. However, it is still controversial whether monitoring is necessary for patients receiving LMWH therapy. Therefore, we conducted a meta-analysis to explore the effect of anti-Xa monitoring on the safety and efficacy of LMWH anticoagulant therapy. METHODS: PubMed, EMBASE, Web of Science and The Cochrane Library were searched on 27 May 2019 for eligible studies published in English. Odds ratio (OR) and 95% confidence intervals (CI) were estimated (Mantel-Haenszel method) using Review Manager version 5.3 software. The systematic review and meta-analysis was performed according to the recommendations of the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. RESULTS AND DISCUSSION: Six studies involving 1617 patients were eligible for our meta-analysis, with 724 patients in the anti-Xa monitoring group and 893 patients in the control group. There was no significant difference in the incidence of bleeding events between the two groups, while the anti-Xa monitoring group had a lower incidence of venous thromboembolism events (OR 0.44, 95% CI 0.29-0.68, P = .0002). Subgroup analysis showed that the incidence of venous thromboembolism events in the anti-Xa monitoring group was lower than that in the control group when the trough level was monitored (OR 0.40, 95% CI 0.25-0.63, P < .0001), while there was no significant difference between the two groups when the peak level was monitored. WHAT IS NEW AND CONCLUSION: Patients receiving LMWH anticoagulant therapy to prevent VTE can benefit from anti-Xa monitoring, for which the trough level may be the more appropriate time status to monitor.